Commit Graph

66 Commits

Author SHA1 Message Date
Michael S. Tsirkin 64b4cc3911 9p/trans_virtio: enable VQs early
virtio spec requires drivers to set DRIVER_OK before using VQs.
This is set automatically after probe returns, but virtio 9p device
adds self to channel list within probe, at which point VQ can be
used in violation of the spec.

To fix, call virtio_device_ready before using VQs.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2014-10-15 10:25:04 +10:30
Linus Torvalds 582076ab16 A bunch of updates and cleanup within the transport layer,
particularly with a focus on RDMA.
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Merge tag 'for-linus-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs

Pull 9p changes from Eric Van Hensbergen:
 "A bunch of updates and cleanup within the transport layer,
  particularly with a focus on RDMA"

* tag 'for-linus-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
  9pnet_rdma: check token type before int conversion
  9pnet: trans_fd : allocate struct p9_trans_fd and struct p9_conn together.
  9pnet: p9_client->conn field is unused. Remove it.
  9P: Get rid of REQ_STATUS_FLSH
  9pnet_rdma: add cancelled()
  9pnet_rdma: update request status during send
  9P: Add cancelled() to the transport functions.
  net: Mark function as static in 9p/client.c
  9P: Add memory barriers to protect request fields over cb/rpc threads handoff
2014-04-11 14:14:57 -07:00
Dominique Martinet 2b6e72ed74 9P: Add memory barriers to protect request fields over cb/rpc threads handoff
We need barriers to guarantee this pattern works as intended:
[w] req->rc, 1		[r] req->status, 1
wmb			rmb
[w] req->status, 1	[r] req->rc

Where the wmb ensures that rc gets written before status,
and the rmb ensures that if you observe status == 1, rc is the new value.

Signed-off-by: Dominique Martinet <dominique.martinet@cea.fr>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2014-03-25 16:37:59 -05:00
Richard Yao b6f52ae2f0 9p/trans_virtio.c: Fix broken zero-copy on vmalloc() buffers
The 9p-virtio transport does zero copy on things larger than 1024 bytes
in size. It accomplishes this by returning the physical addresses of
pages to the virtio-pci device. At present, the translation is usually a
bit shift.

That approach produces an invalid page address when we read/write to
vmalloc buffers, such as those used for Linux kernel modules. Any
attempt to load a Linux kernel module from 9p-virtio produces the
following stack.

[<ffffffff814878ce>] p9_virtio_zc_request+0x45e/0x510
[<ffffffff814814ed>] p9_client_zc_rpc.constprop.16+0xfd/0x4f0
[<ffffffff814839dd>] p9_client_read+0x15d/0x240
[<ffffffff811c8440>] v9fs_fid_readn+0x50/0xa0
[<ffffffff811c84a0>] v9fs_file_readn+0x10/0x20
[<ffffffff811c84e7>] v9fs_file_read+0x37/0x70
[<ffffffff8114e3fb>] vfs_read+0x9b/0x160
[<ffffffff81153571>] kernel_read+0x41/0x60
[<ffffffff810c83ab>] copy_module_from_fd.isra.34+0xfb/0x180

Subsequently, QEMU will die printing:

qemu-system-x86_64: virtio: trying to map MMIO memory

This patch enables 9p-virtio to correctly handle this case. This not
only enables us to load Linux kernel modules off virtfs, but also
enables ZFS file-based vdevs on virtfs to be used without killing QEMU.

Special thanks to both Avi Kivity and Alexander Graf for their
interpretation of QEMU backtraces. Without their guidence, tracking down
this bug would have taken much longer. Also, special thanks to Linus
Torvalds for his insightful explanation of why this should use
is_vmalloc_addr() instead of is_vmalloc_or_module_addr():

https://lkml.org/lkml/2014/2/8/272

Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-02-10 17:48:54 -08:00
Eric Van Hensbergen f94741fd28 net/9p: remove virtio default hack and set appropriate bits instead
A few releases back a patch made virtio the default transport, however
it was done in a way which side-stepped the mechanism put in place to
allow for this selection.  This patch cleans that up while maintaining
virtio as the default transport.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2013-11-23 16:13:36 -06:00
Rusty Russell 855e0c5288 virtio: use size-based config accessors.
This lets the transport do endian conversion if necessary, and insulates
the drivers from the difference.

Most drivers can use the simple helpers virtio_cread() and virtio_cwrite().

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-10-17 10:55:37 +10:30
Michael Marineau e0d6cb9cd3 9p: send uevent after adding/removing mount_tag attribute
This driver adds an attribute to the existing virtio device so a CHANGE
event is required in order udev rules to make use of it. The ADD event
happens before this driver is probed and unlike a more typical driver
like a block device there isn't a higher level device to watch for.

Signed-off-by: Michael Marineau <michael.marineau@coreos.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2013-08-26 10:28:22 -05:00
Linus Torvalds 736a2dd257 Lots of virtio work which wasn't quite ready for last merge window. Plus
I dived into lguest again, reworking the pagetable code so we can move
 the switcher page: our fixmaps sometimes take more than 2MB now...
 
 Cheers,
 Rusty.
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Merge tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux

Pull virtio & lguest updates from Rusty Russell:
 "Lots of virtio work which wasn't quite ready for last merge window.

  Plus I dived into lguest again, reworking the pagetable code so we can
  move the switcher page: our fixmaps sometimes take more than 2MB now..."

Ugh.  Annoying conflicts with the tcm_vhost -> vhost_scsi rename.
Hopefully correctly resolved.

* tag 'virtio-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux: (57 commits)
  caif_virtio: Remove bouncing email addresses
  lguest: improve code readability in lg_cpu_start.
  virtio-net: fill only rx queues which are being used
  lguest: map Switcher below fixmap.
  lguest: cache last cpu we ran on.
  lguest: map Switcher text whenever we allocate a new pagetable.
  lguest: don't share Switcher PTE pages between guests.
  lguest: expost switcher_pages array (as lg_switcher_pages).
  lguest: extract shadow PTE walking / allocating.
  lguest: make check_gpte et. al return bool.
  lguest: assume Switcher text is a single page.
  lguest: rename switcher_page to switcher_pages.
  lguest: remove RESERVE_MEM constant.
  lguest: check vaddr not pgd for Switcher protection.
  lguest: prepare to make SWITCHER_ADDR a variable.
  virtio: console: replace EMFILE with EBUSY for already-open port
  virtio-scsi: reset virtqueue affinity when doing cpu hotplug
  virtio-scsi: introduce multiqueue support
  virtio-scsi: push vq lock/unlock into virtscsi_vq_done
  virtio-scsi: pass struct virtio_scsi to virtqueue completion function
  ...
2013-05-02 14:14:04 -07:00
Rusty Russell 0b36f1adcb 9p/trans_virtio.c: use virtio_add_sgs[]
virtio_add_buf() is going away, replaced with virtio_add_sgs() which
takes multiple terminated scatterlists.

Cc: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2013-03-20 15:45:06 +10:30
Arnd Bergmann dc893e19b5 Revert parts of "hlist: drop the node parameter from iterators"
Commit b67bfe0d42 ("hlist: drop the node parameter from iterators")
did a lot of nice changes but also contains two small hunks that seem to
have slipped in accidentally and have no apparent connection to the
intent of the patch.

This reverts the two extraneous changes.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Peter Senna Tschudin <peter.senna@gmail.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-03-08 15:05:34 -08:00
Sasha Levin b67bfe0d42 hlist: drop the node parameter from iterators
I'm not sure why, but the hlist for each entry iterators were conceived

        list_for_each_entry(pos, head, member)

The hlist ones were greedy and wanted an extra parameter:

        hlist_for_each_entry(tpos, pos, head, member)

Why did they need an extra pos parameter? I'm not quite sure. Not only
they don't really need it, it also prevents the iterator from looking
exactly like the list iterator, which is unfortunate.

Besides the semantic patch, there was some manual work required:

 - Fix up the actual hlist iterators in linux/list.h
 - Fix up the declaration of other iterators based on the hlist ones.
 - A very small amount of places were using the 'node' parameter, this
 was modified to use 'obj->member' instead.
 - Coccinelle didn't handle the hlist_for_each_entry_safe iterator
 properly, so those had to be fixed up manually.

The semantic patch which is mostly the work of Peter Senna Tschudin is here:

@@
iterator name hlist_for_each_entry, hlist_for_each_entry_continue, hlist_for_each_entry_from, hlist_for_each_entry_rcu, hlist_for_each_entry_rcu_bh, hlist_for_each_entry_continue_rcu_bh, for_each_busy_worker, ax25_uid_for_each, ax25_for_each, inet_bind_bucket_for_each, sctp_for_each_hentry, sk_for_each, sk_for_each_rcu, sk_for_each_from, sk_for_each_safe, sk_for_each_bound, hlist_for_each_entry_safe, hlist_for_each_entry_continue_rcu, nr_neigh_for_each, nr_neigh_for_each_safe, nr_node_for_each, nr_node_for_each_safe, for_each_gfn_indirect_valid_sp, for_each_gfn_sp, for_each_host;

type T;
expression a,c,d,e;
identifier b;
statement S;
@@

-T b;
    <+... when != b
(
hlist_for_each_entry(a,
- b,
c, d) S
|
hlist_for_each_entry_continue(a,
- b,
c) S
|
hlist_for_each_entry_from(a,
- b,
c) S
|
hlist_for_each_entry_rcu(a,
- b,
c, d) S
|
hlist_for_each_entry_rcu_bh(a,
- b,
c, d) S
|
hlist_for_each_entry_continue_rcu_bh(a,
- b,
c) S
|
for_each_busy_worker(a, c,
- b,
d) S
|
ax25_uid_for_each(a,
- b,
c) S
|
ax25_for_each(a,
- b,
c) S
|
inet_bind_bucket_for_each(a,
- b,
c) S
|
sctp_for_each_hentry(a,
- b,
c) S
|
sk_for_each(a,
- b,
c) S
|
sk_for_each_rcu(a,
- b,
c) S
|
sk_for_each_from
-(a, b)
+(a)
S
+ sk_for_each_from(a) S
|
sk_for_each_safe(a,
- b,
c, d) S
|
sk_for_each_bound(a,
- b,
c) S
|
hlist_for_each_entry_safe(a,
- b,
c, d, e) S
|
hlist_for_each_entry_continue_rcu(a,
- b,
c) S
|
nr_neigh_for_each(a,
- b,
c) S
|
nr_neigh_for_each_safe(a,
- b,
c, d) S
|
nr_node_for_each(a,
- b,
c) S
|
nr_node_for_each_safe(a,
- b,
c, d) S
|
- for_each_gfn_sp(a, c, d, b) S
+ for_each_gfn_sp(a, c, d) S
|
- for_each_gfn_indirect_valid_sp(a, c, d, b) S
+ for_each_gfn_indirect_valid_sp(a, c, d) S
|
for_each_host(a,
- b,
c) S
|
for_each_host_safe(a,
- b,
c, d) S
|
for_each_mesh_entry(a,
- b,
c, d) S
)
    ...+>

[akpm@linux-foundation.org: drop bogus change from net/ipv4/raw.c]
[akpm@linux-foundation.org: drop bogus hunk from net/ipv6/raw.c]
[akpm@linux-foundation.org: checkpatch fixes]
[akpm@linux-foundation.org: fix warnings]
[akpm@linux-foudnation.org: redo intrusive kvm changes]
Tested-by: Peter Senna Tschudin <peter.senna@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-27 19:10:24 -08:00
Zhang Yanfei 7293bfba03 net: change type of virtio_chan->p9_max_pages
This member of struct virtio_chan is calculated from nr_free_buffer_pages
so change its type to unsigned long in case of overflow.

Signed-off-by: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Ron Minnich <rminnich@sandia.gov>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-02-23 17:50:22 -08:00
Will Deacon b9cdc88df8 virtio: 9p: correctly pass physical address to userspace for high pages
When using a virtio transport, the 9p net device may pass the physical
address of a kernel buffer to userspace via a scatterlist inside a
virtqueue. If the kernel buffer is mapped outside of the linear mapping
(e.g. highmem), then virt_to_page will return a bogus value and we will
populate the scatterlist with junk.

This patch uses kmap_to_page when populating the page array for a kernel
buffer.

Cc: stable@kernel.org
Cc: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-10-22 18:19:36 +10:30
Ben Hutchings 2c53040f01 net: Fix (nearly-)kernel-doc comments for various functions
Fix incorrect start markers, wrapped summary lines, missing section
breaks, incorrect separators, and some name mismatches.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-10 23:13:45 -07:00
Sasha Levin 5fcb08befa 9p: BUG before corrupting memory
The BUG_ON() in pack_sg_list() would get triggered only one time after we've
corrupted some memory by sg_set_buf() into an invalid sg buffer.

I'm still working on figuring out why I manage to trigger that bug...

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2012-06-11 10:29:07 -05:00
Sasha Levin 991ad9ec39 9p: disconnect channel when PCI device is removed
When a virtio_9p pci device is being removed, we should close down any
active channels and free up resources, we're not supposed to BUG() if there's
still an open channel since it's a valid case when removing the PCI device.

Otherwise, removing the PCI device with an open channel would cause the
following BUG():

[ 1184.671416] ------------[ cut here ]------------
[ 1184.672057] kernel BUG at net/9p/trans_virtio.c:618!
[ 1184.672057] invalid opcode: 0000 [#1] PREEMPT SMP
[ 1184.672057] CPU 3
[ 1184.672057] Pid: 5, comm: kworker/u:0 Tainted: G        W    3.4.0-rc2-next-20120413-sasha-dirty #76
[ 1184.672057] RIP: 0010:[<ffffffff825c9116>]  [<ffffffff825c9116>] p9_virtio_remove+0x16/0x90
[ 1184.672057] RSP: 0018:ffff88000d653ac0  EFLAGS: 00010202
[ 1184.672057] RAX: ffffffff836bfb40 RBX: ffff88000c9b2148 RCX: ffff88000d658978
[ 1184.672057] RDX: 0000000000000006 RSI: 0000000000000000 RDI: ffff880028868000
[ 1184.672057] RBP: ffff88000d653ad0 R08: 0000000000000000 R09: 0000000000000000
[ 1184.672057] R10: 0000000000000000 R11: 0000000000000001 R12: ffff880028868000
[ 1184.672057] R13: ffffffff835aa7c0 R14: ffff880041630000 R15: ffff88000d653da0
[ 1184.672057] FS:  0000000000000000(0000) GS:ffff880035a00000(0000) knlGS:0000000000000000
[ 1184.672057] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 1184.672057] CR2: 0000000001181000 CR3: 000000000eba1000 CR4: 00000000000406e0
[ 1184.672057] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
x000000000117a190 *[ 1184.672057] DR3: 00000000000000**
00 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[ 1184.672057] Process kworker/u:0 (pid: 5, threadinfo ffff88000d652000, task ffff88000d658000)
[ 1184.672057] Stack:
[ 1184.672057]  ffff880028868000 ffffffff836bfb40 ffff88000d653af0 ffffffff8193661b
[ 1184.672057]  ffff880028868008 ffffffff836bfb40 ffff88000d653b10 ffffffff81af1c81
[ 1184.672057]  ffff880028868068 ffff880028868008 ffff88000d653b30 ffffffff81af257a
[ 1184.795301] Call Trace:
[ 1184.795301]  [<ffffffff8193661b>] virtio_dev_remove+0x1b/0x60
[ 1184.795301]  [<ffffffff81af1c81>] __device_release_driver+0x81/0xd0
[ 1184.795301]  [<ffffffff81af257a>] device_release_driver+0x2a/0x40
[ 1184.795301]  [<ffffffff81af0d48>] bus_remove_device+0x138/0x150
[ 1184.795301]  [<ffffffff81aef08d>] device_del+0x14d/0x1b0
[ 1184.795301]  [<ffffffff81aef138>] device_unregister+0x48/0x60
[ 1184.795301]  [<ffffffff8193694d>] unregister_virtio_device+0xd/0x10
[ 1184.795301]  [<ffffffff8265fc74>] virtio_pci_remove+0x2a/0x6c
[ 1184.795301]  [<ffffffff818a95ad>] pci_device_remove+0x4d/0x110
[ 1184.795301]  [<ffffffff81af1c81>] __device_release_driver+0x81/0xd0
[ 1184.795301]  [<ffffffff81af257a>] device_release_driver+0x2a/0x40
[ 1184.795301]  [<ffffffff81af0d48>] bus_remove_device+0x138/0x150
[ 1184.795301]  [<ffffffff81aef08d>] device_del+0x14d/0x1b0
[ 1184.795301]  [<ffffffff81aef138>] device_unregister+0x48/0x60
[ 1184.795301]  [<ffffffff818a36fa>] pci_stop_bus_device+0x6a/0x90
[ 1184.795301]  [<ffffffff818a3791>] pci_stop_and_remove_bus_device+0x11/0x20
[ 1184.795301]  [<ffffffff818c21d9>] remove_callback+0x9/0x10
[ 1184.795301]  [<ffffffff81252d91>] sysfs_schedule_callback_work+0x21/0x60
[ 1184.795301]  [<ffffffff810cb1a1>] process_one_work+0x281/0x430
[ 1184.795301]  [<ffffffff810cb140>] ? process_one_work+0x220/0x430
[ 1184.795301]  [<ffffffff81252d70>] ? sysfs_read_file+0x1c0/0x1c0
[ 1184.795301]  [<ffffffff810cc613>] worker_thread+0x1f3/0x320
[ 1184.795301]  [<ffffffff810cc420>] ? manage_workers.clone.13+0x130/0x130
[ 1184.795301]  [<ffffffff810d30b2>] kthread+0xb2/0xc0
[ 1184.795301]  [<ffffffff826783f4>] kernel_thread_helper+0x4/0x10
[ 1184.795301]  [<ffffffff810deb18>] ? finish_task_switch+0x78/0xf0
[ 1184.795301]  [<ffffffff82676574>] ? retint_restore_args+0x13/0x13
[ 1184.795301]  [<ffffffff810d3000>] ? kthread_flush_work_fn+0x10/0x10
[ 1184.795301]  [<ffffffff826783f0>] ? gs_change+0x13/0x13
[ 1184.795301] Code: c1 9e 0a 00 48 83 c4 08 5b c9 c3 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 54 49 89 fc 53 48 8b 9f a8 04 00 00 80 3b 00 74 0a <0f> 0b 0f 1f 84 00 00 00 00 00 48 8b 87 88 04 00 00 ff 50 30 31
[ 1184.795301] RIP  [<ffffffff825c9116>] p9_virtio_remove+0x16/0x90
[ 1184.795301]  RSP <ffff88000d653ac0>
[ 1184.952618] ---[ end trace a307b3ed40206b4c ]---

Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2012-05-22 12:16:10 +09:30
Rusty Russell f96fde41f7 virtio: rename virtqueue_add_buf_gfp to virtqueue_add_buf
Remove wrapper functions. This makes the allocation type explicit in
all callers; I used GPF_KERNEL where it seemed obvious, left it at
GFP_ATOMIC otherwise.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2012-01-12 15:44:42 +10:30
Joe Perches 5d3851530d 9p: Reduce object size with CONFIG_NET_9P_DEBUG
Reduce object size by deduplicating formats.

Use vsprintf extension %pV.
Rename P9_DPRINTK uses to p9_debug, align arguments.
Add function for _p9_debug and macro to add __func__.
Add missing "\n"s to p9_debug uses.
Remove embedded function names as p9_debug adds it.
Remove P9_EPRINTK macro and convert use to pr_<level>.
Add and use pr_fmt and pr_<level>.

$ size fs/9p/built-in.o*
   text	   data	    bss	    dec	    hex	filename
  62133	    984	  16000	  79117	  1350d	fs/9p/built-in.o.new
  67342	    984	  16928	  85254	  14d06	fs/9p/built-in.o.old
$ size net/9p/built-in.o*
   text	   data	    bss	    dec	    hex	filename
  88792	   4148	  22024	 114964	  1c114	net/9p/built-in.o.new
  94072	   4148	  23232	 121452	  1da6c	net/9p/built-in.o.old

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2012-01-05 10:51:44 -06:00
Aneesh Kumar K.V abfa034e4b fs/9p: Update zero-copy implementation in 9p
* remove lot of update to different data structure
* add a seperate callback for zero copy request.
* above makes non zero copy code path simpler
* remove conditionalizing TREAD/TREADDIR/TWRITE in the zero copy path
* Fix the dotu p9_check_errors with zero copy. Add sufficient doc around
* Add support for both in and output buffers in zero copy callback
* pin and unpin pages in the same context
* use helpers instead of defining page offset and rest of page ourself
* Fix mem leak in p9_check_errors
* Remove 'E' and 'F' in p9pdu_vwritef

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-10-24 11:13:11 -05:00
Aneesh Kumar K.V b49d8b5d70 net/9p: Fix kernel crash with msize 512K
With msize equal to 512K (PAGE_SIZE * VIRTQUEUE_NUM), we hit multiple
crashes. This patch fix those.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-09-06 08:17:15 -05:00
jvrao 7f781679dd VirtIO can transfer VIRTQUEUE_NUM of pages.
Signed-off-by: Venkateswararao Jujjuri "<jvrao@linux.vnet.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-07-23 09:32:48 -05:00
jvrao 114e6f3a5e Fix the size of receive buffer packing onto VirtIO ring.
Signed-off-by: Venkateswararao Jujjuri "<jvrao@linux.vnet.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-07-23 09:32:47 -05:00
Aneesh Kumar K.V bd8c8ade6b 9p: Fix sparse error
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-04-15 15:26:14 -05:00
Venkateswararao Jujjuri (JV) 68da9ba4ee [net/9p]: Introduce basic flow-control for VirtIO transport.
Recent zerocopy work in the 9P VirtIO transport maps and pins
user buffers into kernel memory for the server to work on them.
Since the user process can initiate this kind of pinning with a simple
read/write call, thousands of IO threads initiated by the user process can
hog the system resources and could result into denial of service.

This patch introduces flow control to avoid that extreme scenario.

The ceiling limit to avoid denial of service attacks is set to relatively
high (nr_free_pagecache_pages()/4) so that it won't interfere with
regular usage, but can step in extreme cases to limit the total system
hang. Since we don't have a global structure to accommodate this variable,
I choose the virtio_chan as the home for this.

Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Reviewed-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-03-22 16:32:50 -05:00
Venkateswararao Jujjuri (JV) 316ad5501c [net/9p] Don't re-pin pages on retrying virtqueue_add_buf().
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-03-22 16:32:48 -05:00
Venkateswararao Jujjuri (JV) a01a984035 [net/9p] Set the condition just before waking up.
Given that the sprious wake-ups are common, we need to move the
condition setting right next to the wake_up().  After setting the condition
to req->status = REQ_STATUS_RCVD, sprious wakeups may cause the
virtqueue back on the free list for someone else to use.
This may result in kernel panic while relasing the pinned pages
in p9_release_req_pages().

Also rearranged the while loop in req_done() for better redability.

Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-03-22 16:32:47 -05:00
Venkateswararao Jujjuri (JV) 53bda3e5b4 [net/9p] unconditional wake_up to proc waiting for space on VirtIO ring
Process may wait to get space on VirtIO ring to send a transaction to
VirtFS server. Current code just does a conditional wake_up() which
means only one process will be woken up even if multiple processes
are waiting.

This fix makes the wake_up unconditional. Hence we won't have any
processes waiting for-ever.

Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-03-22 16:32:19 -05:00
Venkateswararao Jujjuri (JV) 6f69c395ce [net/9p] Add preferences to transport layer.
This patch adds preferences field to the p9_trans_module.
Through this, now transport layer can express its preference about the
payload. i.e if payload neds to be part of the PDU or it prefers it
to be sent sepearetly so that the transport layer can handle it in
a better way.

Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-03-15 09:57:35 -05:00
Venkateswararao Jujjuri (JV) 4038866dab [net/9p] Add gup/zero_copy support to VirtIO transport layer.
Modify p9_virtio_request() and req_done() functions to support
additional payload sent down to the transport layer through
tc->pubuf and tc->pkbuf.

Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2011-03-15 09:57:35 -05:00
Venkateswararao Jujjuri (JV) 52f44e0d08 net/9p: Add waitq to VirtIO transport.
If there is not enough space for the PDU on the VirtIO ring, current
code returns -EIO propagating the error to user.

This patch introduced a wqit_queue on the channel, and lets the process
wait on this queue until VirtIO ring frees up.

Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2010-10-28 09:08:48 -05:00
Venkateswararao Jujjuri (JV) 419b39561e [net/9p]Serialize virtqueue operations to make VirtIO transport SMP safe.
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2010-10-28 09:08:48 -05:00
Sven Eckelmann 0b20406cda net/9p: Mount only matching virtio channels
p9_virtio_create will only compare the the channel's tag characters
against the device name till the end of the channel's tag but not till
the end of the device name. This means that if a user defines channels
with the tags foo and foobar then he would mount foo when he requested
foonot and may mount foo when he requested foobar.

Thus it is necessary to check both string lengths against each other in
case of a successful partial string match.

Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-27 15:54:44 -07:00
Michael S. Tsirkin dc3f5e68f8 trans_virtio: use virtqueue_xxx wrappers
Switch trans_virtio to new virtqueue_xxx wrappers.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-05-19 22:15:45 +09:30
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Aneesh Kumar K.V 86c8437383 net/9p: Add sysfs mount_tag file for virtio 9P device
This adds a new file for virtio 9P device. The file
contain details of the mount device name that should
be used to mount the 9P file system.

Ex: /sys/devices/virtio-pci/virtio1/mount_tag  file now
contian the tag name to be used to mount the 9P file system.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2010-03-13 08:57:29 -06:00
Aneesh Kumar K.V 97ee9b0257 net/9p: Use the tag name in the config space for identifying mount point
This patch use the tag name in the config space to identify the
mount device. The the virtio device name depend on the enumeration
order of the device and may not remain the same across multiple boots
So we use the tag name which is set via qemu option to uniquely identify
the mount device

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2010-03-13 08:57:28 -06:00
Aneesh Kumar K.V c1a7c22620 net/9p: Handle mount errors correctly.
With this patch we have

# mount -t 9p -o trans=virtio virtio2 /mnt/
# mount -t 9p -o trans=virtio virtio2 /mnt/
mount: virtio2 already mounted or /mnt/ busy
mount: according to mtab, virtio2 is already mounted on /mnt
# mount -t 9p -o trans=virtio virtio3 /mnt/ -o debug=0xfff
mount: special device virtio3 does not exist

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2010-03-05 15:04:41 -06:00
Aneesh Kumar K.V 37c1209d41 net/9p: Remove MAX_9P_CHAN limit
Use a list to track the channel instead of statically
allocated array

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2010-03-05 15:04:41 -06:00
Aneesh Kumar K.V f75580c4af net/9p: Add multi channel support.
This is needed for supporting multiple mount points.

We can find out the device names to be used with mount by checking

/sys/devices/virtio-pci/virtio*/device file

if the device file have value 9 then the specific virtio device can
be used for mounting.

ex:
 #cat /sys/devices/virtio-pci/virtio1/device
 9

now we can mount using
# mount -t 9p -o trans=virtio virtio1  /mnt/

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2010-03-05 15:04:41 -06:00
Aneesh Kumar K.V fb786100f7 9p: Fix the kernel crash on a failed mount
The patch fix the crash repoted below

[   15.149907] BUG: unable to handle kernel NULL pointer dereference at 00000001
[   15.150806] IP: [<c140b886>] p9_virtio_close+0x18/0x24
.....
....
[   15.150806] Call Trace:
[   15.150806]  [<c1408e78>] ? p9_client_destroy+0x3f/0x163
[   15.150806]  [<c1409342>] ? p9_client_create+0x25f/0x270
[   15.150806]  [<c1063b72>] ? trace_hardirqs_on+0xb/0xd
[   15.150806]  [<c11ed4e8>] ? match_token+0x64/0x164
[   15.150806]  [<c1175e8d>] ? v9fs_session_init+0x2f1/0x3c8
[   15.150806]  [<c109cfc9>] ? kmem_cache_alloc+0x98/0xb8
[   15.150806]  [<c1063b72>] ? trace_hardirqs_on+0xb/0xd
[   15.150806]  [<c1173dd1>] ? v9fs_get_sb+0x47/0x1e8
[   15.150806]  [<c1173dea>] ? v9fs_get_sb+0x60/0x1e8
[   15.150806]  [<c10a2e77>] ? vfs_kern_mount+0x81/0x11a
[   15.150806]  [<c10a2f55>] ? do_kern_mount+0x33/0xbe
[   15.150806]  [<c10b40b9>] ? do_mount+0x654/0x6b3
[   15.150806]  [<c1038949>] ? do_page_fault+0x0/0x284
[   15.150806]  [<c10b28ec>] ? copy_mount_options+0x73/0xd2
[   15.150806]  [<c10b4179>] ? sys_mount+0x61/0x94
[   15.150806]  [<c14284e9>] ? syscall_call+0x7/0xb
....
[   15.203562] ---[ end trace 1dd159357709eb4b ]---
[

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2010-02-08 17:25:33 -06:00
Eric Van Hensbergen 562ada6120 net/9p: fix virtio transport to correctly update status on connect
The 9p virtio transport was not updating its connection status correctly
preventing it from being able to mount the server.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2010-02-08 14:13:30 -06:00
Christian Borntraeger e95646c3ec virtio: let header files include virtio_ids.h
Rusty,

commit 3ca4f5ca73
    virtio: add virtio IDs file
moved all device IDs into a single file. While the change itself is
a very good one, it can break userspace applications. For example
if a userspace tool wanted to get the ID of virtio_net it used to
include virtio_net.h. This does no longer work, since virtio_net.h
does not include virtio_ids.h.
This patch moves all "#include <linux/virtio_ids.h>" from the C
files into the header files, making the header files compatible with
the old ones.

In addition, this patch exports virtio_ids.h to userspace.

CC: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-10-22 16:39:28 +10:30
Fernando Luis Vazquez Cao 3ca4f5ca73 virtio: add virtio IDs file
Virtio IDs are spread all over the tree which makes assigning new IDs
bothersome. Putting them together should make the process less error-prone.

Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-09-23 22:26:32 +09:30
Fernando Luis Vazquez Cao 3a20210dc2 virtio: get rid of redundant VIRTIO_ID_9P definition
VIRTIO_ID_9P is already defined in include/linux/virtio_9p.h
so use that definition instead.

Signed-off-by: Fernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
2009-09-23 22:26:32 +09:30
Rusty Russell 3c1b27d504 virtio: make add_buf return capacity remaining
This API change means that virtio_net can tell how much capacity
remains for buffers.  It's necessarily fuzzy, since
VIRTIO_RING_F_INDIRECT_DESC means we can fit any number of descriptors
in one, *if* we can kmalloc.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Dinesh Subhraveti <dineshs@us.ibm.com>
2009-09-23 22:26:31 +09:30
Abhishek Kulkarni 0e15597ebf 9p: minor comment fixes
Fix the comments -- mostly the improper and/or missing descriptions
of function parameters.

Signed-off-by: Abhishek Kulkarni <adkulkar@umail.iu.edu>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2009-08-17 16:27:57 -05:00
Michael S. Tsirkin d2a7ddda9f virtio: find_vqs/del_vqs virtio operations
This replaces find_vq/del_vq with find_vqs/del_vqs virtio operations,
and updates all drivers. This is needed for MSI support, because MSI
needs to know the total number of vectors upfront.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (+ lguest/9p compile fixes)
2009-06-12 22:16:36 +09:30
Rusty Russell 9499f5e7ed virtio: add names to virtqueue struct, mapping from devices to queues.
Add a linked list of all virtqueues for a virtio device: this helps for
debugging and is also needed for upcoming interface change.

Also, add a "name" field for clearer debug messages.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2009-06-12 22:16:36 +09:30
Latchesar Ionkov 1bab88b231 net/9p: handle correctly interrupted 9P requests
Currently the 9p code crashes when a operation is interrupted, i.e. for
example when the user presses ^C while reading from a file.

This patch fixes the code that is responsible for interruption and flushing
of 9P operations.

Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
2009-04-05 16:54:53 -05:00
Eric Van Hensbergen 91b8534fa8 9p: make rpc code common and rework flush code
This code moves the rpc function to the common client base,
reorganizes the flush code to be more simple and stable, and
makes the necessary adjustments to the underlying transports
to adapt to the new structure.

This reduces the overall amount of code duplication between the
transports and should make adding new transports more straightforward.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2008-10-17 11:04:42 -05:00